Mississippi Hobsons

I am searching for my mothers HOBSON family of Water Valley,Miss.
I only know the first names of some of her siblings.
Katherine and Bill.Bill worked for the railroad.Most of her family died early either from smallpox or drowning.
She had an aunt and uncle named Bill and Mary Martin or Morton.
They later lived in Okla.
Her mother died when she was one year old and her father when she was two.I assume that her aunt Mary raised her.